Internal combustion engine



' Jan. 19, 1932 g, EDWARDS 1,841,796

INTERNAL COMBUSTION ENGINE Filed Feb. 4'. 1-929 gwuentoz I 15 f1 E7. 5'' .HEEBEET Z1 Erwazzzs:

Patented Jan. 19, 1932 UNITED STATES PATENT OFFICE HERBERT C. EDWARDS, OF DETROIT, MICHIGAN, ASSIGNOR TO PACKARD MOTOR OAR COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN INTERNAL COMBUSTION ENGINE Application filed February 4, 1929; Serial No. 337,217.

This invention relates to internal combus-- tion engines and more. particularly to pistons for internal combustion engines.

In engines in which the explosion temperatures are high, or where the combustion period is prolonged, and more especially in selfigniting engines where combustion occurs through compression of air, the piston head becomes very hot. While this heat may be an advantage in some instances to assist in vaporization of the fuel, it is under any circumstances very detrimental to the life of the piston when excessive, and where the head is formed as a thin wall for lightness or other purposes, such undesirable conditions become more pronounced. Excessive heat will pit the piston head and often distort it within a short time so that inefficient or impossible working-conditions result. An object of my invention is to provide a piston in which these undesirable conditions are eliminated under normal compression temperatures.

Another object of my invention is to provide a piston for engines in which heat will be absorbed from the head during operation.

Still another object of my invention is to provide separate brine-containing compartments in a piston which are arranged to reduce the normal temperature of the head.

These and other objects of the invention will appear from the following description taken in connection with the accompanying drawings which form part of this specification and in which i F ig. 1 is a plan view of a piston embodying my invention; and I Fig. 2 is a side elevation of the same partially in section.

Referring now to the drawings by characters of reference, 10 represents the head of a piston for combustion engines from which depends the annular skirt 11. The upper end of the skirt is provided with spaced ring 45 grooves 12 which are arranged in a plane above the aligned bosses 13 which receive'the rod pin (not shown).

The piston illustrated is designed especially for Diesel engines, or engines of a similar type in which the fuel is ignited by'the heat of compressed air; however, this invention applies equally well to pistons in which lower compression is used. In order to withstand the high explosive pressures, the head wall of the piston is of substantial thickness, and furthermore becomes very hot during operation of the engine. The heat develo ed in the engine head often will result in pitting and other distortion which renders the piston either inefficient or useless.

In order to prevent excessive temperature in the head, I propose to associate with the piston, preferably in a self-contained manner, means for absorbing and transferring some of the heat generating in the head of the piston during engine operation. I provide the piston skirt with longitudinal extensions 20 having drilled passages forming compartments 14,- one end of which projects into the head and the other end of which opens through the bottom of the skirt and is closed by plugs 15 screwed into the end thereof. Such compartments are artially filled with a medium 9 having heat absorbing qualities, such as lithium, potassium, or some suitable brine solution. It is preferable that the solution be such that a relatively high temperature will be generated in the piston before the medium becomes liquid, so that heat will not be abstracted generally from the head until a high temperature is generated whereby the advantage of the heated piston for assisting fuel vaporization will not be interfered with. During reciprocation of the piston, the heat absorbing medium, whether in solution or in crystal form, will be agitated and sweep against the interior walls of the compartments, and as the head is the hottest portion of the piston, heat from the compartment walls adjacent there- 90 to will be absorbed by the mediun. If the skirt of the piston is of lower temperature than the heat transfer medium, naturally heat absorbed from the head will be transferred to the skirt from the medium.

The medium in the chambers Will reduce the temperature of the head and Will under normal operating temperatures maintain a head temperature which will not cause pitting or distortion of the piston head, thereby allowing maximum efficiency and insuring a long life for the piston, as Well as permitting a lighter head Wall.

The form of my invention shown and described is to be considered merely as a preferred one, and it is intended that the invention be limited only by the scope of the applended claims.

aving thus described my invention, What I claim and desire to secure by Letters Patent is:

1. A piston having a head and a depend ing skirt, said skirt having a plurality of separated chambers therein adapted to contain a heat absorbing medium, said chambers extending adjacent the head.

2. A piston having a head and a depending skirt, said skirt having a plurality of separated holes drilled therein, and closure members for said holes, the holes being adapted to pontain a heat absorbing medium.

3. A piston having a head, a skirt, and a plurality of isolated means contained in and extending lengthwise of said skirt for absorbing heat from said head.

4. A piston having a head, a depending skirt, and a. plurality of isolated heat absorbing means enclosed within the Wall forming said skirt.

5, A piston having a head, a depending skirt, said skirt being formed with a plurality In testimopiy whereof I aflix my si nature.

of spaced extensions having interior compartments adapted to contain'a heat absorbing medium.

6. A piston having a head, a skirt depending from said head, said skirt having spaced extensions axially arranged in spaced relation and merging into said head, said ex tensions having axially extending compartments therein, and a heat absorbing medium in said compartments for removing heat from said head.

7. A piston having a head, a skirt depending from said head, spaced extensions projecting from the interior of said skirt and merging into said head, axially extending openings in said extensions, plugs for closing said openings, and heat absorbing means housed within said openings, said means being free to move Within said openings.

8. A piston having a head, a skirt depending from said head, longitudinally extending compartments in said skirt and head, and a heat absorbing medium in said compartments.

ERBERT o. EnWAhns. 

